Screw operated linkage mechanism for slide gate

ABSTRACT

Operating mechanism for a gate slidable between closed and open positions relative to the discharge opening of a hopper outlet assembly. The operating mechanism includes a rotatable threaded operating shaft extending transversely of the path of movement of the gate, thrust bearing means threaded on the operating shaft, and linkage means connected between the thrust bearing means, hopper outlet assembly, and the gate, whereby the gate is moved toward the operating shaft as the latter is rotated in one direction and away from the operating shaft upon rotation of the latter in the other direction.

.PATENTEU JUN H971 3581.673

sum 1 or 2 SCREW OPERATED LINKAGE MECHANISM FOR SLIDE GATE FIELD OF THE INVENTION The present invention relates generally to a hopper outlet assembly which is adapted for use, for example, in connection with railroad hopper cars, and more particularly to operating mechanism for moving a slide gate, associated with the hopper outlet assembly, between closed and open positions.

SUMMARY OF THE INVENTION The operating mechanism of the present invention is associated with a slide gate movable in the frame means of a hopper outlet assembly between closed and open positions relative to the discharge opening of the assembly. In accordance with the present invention, a rotatable threaded operating shaft is arranged transversely of the path of movement of the gate, and serves, through thrust bearing means threaded on the operating shaft and linkage means, to effect opening and closing movement of the gate upon rotation of the operating shaft.

More particularly, the operating shaft is provided with righthand and left-hand threaded sections, thrust bearing members are threaded on these sections, and pivotal force transmitting link members are connected between the thrust bearing members and the gate. Upon rotation of the operating shaft, the thrust bearing members are moved axially along the shaft and, in conjunction with the force transmitting link members, move the gate toward or away from the operating shaft.

Additionally, the ends of the operating shaft are journaled in slide members slidably engaged along the frame means, and pivotal force reaction link members, located on the side of the operating shaft opposite the force transmitting link members, are connected between the thrust bearing members and the frame means. With this arrangement, the operating shaft moves along the frame means transversely of the axis of rotation as the gate is moved to open or closed position.

Still further, to minimize side movement of the operating shaft and gate transversely of the path of movement of the gate between closed and open positions, pivotal auxiliary link members are connected between the centers of the force transmitting and force reaction link members and the slide members.

The foregoing operating mechanism initially effects a slow rate of movement of the gate, with a relatively high mechanical advantage, at the commencement of opening of the gate when the load thereon is greatest, and thereafter effects a steadily increasing rate of movement of the gate, witha corresponding decrease in mechanical advantage, as the gate moves to full open position and the load thereon decreases. These desirable characteristics of gate movement and attendant mechanical advantage cannot be provided in conventional gate operating mechanism comprised, for example, of rack and pinion means incorporating a gear reduction unit. Moreover, because the threaded operating shaft can be formed with rolled threads and the various link members can be formed of flat stock, and in view of the elimination of castings, gear housings and the like, the operating mechanism of the present invention is less expensive to fabricate and assemble than the conventional rack and pinion type operating mechanism noted above.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. ll'is a plan view of a hopper outlet assembly incorporating the slide gate operating mechanism of the present invention, with the slide gate being shown in closed position;

FIG. 2 is a sectional view, taken substantially along the line 2-2 in FIG. I, looking in the direction indicated by the arrows;

FIG. 3 is an enlarged partial plan view, with portions being broken away and shown in section, of the hopper outlet assembly of FIG. I, and shows the slide gate operating mechanism as positioned when the slide gate is in full open position; and

FIG. 4 is a sectional view, taken substantially along the line 4-4 in FIG. 3, looking the direction indicated by the arrows.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. I and 2, there is indicated generally by the reference numeral 10 the lower end portion of a hopper, for example, ofa railroad hopper car which may be of either the side pocket type or the center-flow type. Associated with the hopper I0 is a hopper outlet assembly 12 incorporating the principles ofthe present invention.

The hopper outlet assembly 12 is comprised of a generally rectangular main frame I4 having a sidewall 16 with a lower inwardly directed channel flange portion 18, a sidewall 20 with a lower inwardly directed channel flange portion 22, an end wall 24 with a lower inwardly directed channel flange portion 26, and an end wall 28. Extending between the side channel flange portions 18 and 22 and spaced slightly below the end wall 28 is a transverse channel flange member 30. The channel flanges 18, 22, 26 and 30 serve to define the perimeter of a discharge opening in the main frame 14 through which lading can flow by gravity from the hopper l0.

Extending from the main frame 14 is a secondary frame 32 which comprises parallel side guideways 34 and 36, for example, of T-shape cross section. The one ends of the guideways 34 and 36 are suitably secured to the main frame 14 adjacent the channel flange member 30, while the other ends of the guideways are interconnected by a transverse angle flange or end frame member 38. The top surfaces of the guideways 34 and 36 and frame member 38 lie in a plane common to the plane of the top surfaces of the channel flanges 18, 22, 26 and 30. Arranged for sliding movement along the aforesaid guideways and channel flanges is a generally rectangular slide gate 40. When the leading edge of the gate 40 is disposed across the channel flange 26, the gate serves to close the discharge opening in the main frame 14.

The operating mechanism of the present invention for effecting movement of the slide gate 40 between closed and open positions comprises an operating shaft 42 extending transversely of the guideways 34 and 36 and of the path of movement of the gate 40. The operating shaft 42 is formed with a right-hand threaded section 44 and a left-hand threaded section 46, and an Acme thread design is preferably used so that a large lead may be provided. The operating shaft is rotatably mounted on the hopper outlet assembly 12 by means of a pair of slide members 48. Each of the slide members 48 carries a bearing member 49 in which the adjacent portion of the operating shaft 42 is joumaled, and includes an upper offset arm portion 50 and a bottom plate presenting a lower arm portion 51. The vertically spaced arm portions 50 and 51, as shown in FIG. 4, are slidably engaged about the adjacent side guideways 34 and 36. Thus, the operating shaft 42 isfree to slide along the guideways 34 and 36, and yet is restrained against upward movement relative thereto.

Threaded on each of the sections 44 and 46 of the operating shaft 42 is a thrust bearing member 52 having opposed side flanges 54 and 56. Connected between the thrust bearing members 52 and the gate 40 is force transmitting linkage means comprised of a pair of force transmitting link members 58. Each of the link members 58 is pivotally connected at one end by a pin member 60 to the side flange 54 of one of the thrust bearing members 52, and is pivotally connected at the other end by a pin member 62 to the gate 40. Correspondingly, there is connected between the thrust bearing members 52 and the secondary frame 32 force reaction linkage means comprised of a pair of force reaction link members 64. Each link member 64 is pivotally connected at one end by a pin member 66 to the side flange 56 of one of the bearing members 52, and is pivotally connected at the other end by a pin member 68 to a cross brace 70 secured to the adjacent corner of the secondary frame 32. The operating mechanism further includes four auxiliary link members 72. Each link member 72 is pivotally connected at one end by a pin member 74 to one of the force transmitting and force reaction link members 58 and 64 intermediate of the ends thereof and is pivotally connected at the other end by a pin member 76 to the adjacent slide member 48.

When the slide gate 40 is positioned across the discharge opening of the main frame 14 as shown in FIG. 1 and 2, the discharge opening is closed thereby for retaining lading within the associated hopper 10. When it is desired to discharge lading through the discharge opening, the operating shaft 42 is rotated clockwise as viewed in FIG. 2. Such rotation of the shaft 42 effects threaded movement of the thrust bearing members 52 toward each other axially along the operating shaft 42. As the thrust bearing members 52 move toward each other, the force reaction link members 64 are retracted laterally inwardly and slide the operating shaft 42 in the direction of the transverse frame member 38 of the secondary frame 32. At the same time the force transmitting link members 58 are also retracted laterally inwardly and draw the slide gate 40 toward the operating shaft 42. In this manner, the slide gate 40 is moved from the closed position shown in FIGS. 1 and 2 to the open position shown in FIG. 3. At the commencement of opening of the gate 40 when the load imposed thereon by the lading within the hopper is greatest, the operating mechanism initially effects a slow rate of movement of the gate with a relatively high mechanical advantage. Thereafter, the operating mechanism effects a steadily increasing rate of movement of the gate, with a corresponding decrease in mechanical advantage, as the gate moves to full open position and the load thereon decreases.

To return the slide gate 40 to closed position, the operating shaft 42 is rotated counterclockwise as viewed in FIG. 3v The thrust bearing members 52 are thereby moved outwardly along the operating shaft 42, and the force transmitting link members 58 and the force reaction link members 64 are gradually extended laterally outwardly for moving the operat ing shaft 42 away from the transverse frame member 38 and correspondingly moving the slide gate 40 away from the operating shaft 42. When the o erating mechanism is returned to the position shown in FIGS. 1 and 2, the slide gate 40 is again disposed in a fully closed position. During opening and closing movement of the slide gate 40, the auxiliary link members 72 stabilize the operating linkage means and minimize side movement of the operating shaft 42 and slide gate 40 transversely of the path of movement of the latter.

While there has been shown and described a preferred embodiment of the present invention, it will be understood by those skilled in the art that various rearrangements and modifications may be made therein without departing from the spirit and scope of the invention.

I claim:

1. In a hopper outlet assembly including a main frame having a discharge opening through which lading can flow by gravity, a slide gate slidably movable between closed and open positions relative to the discharge opening, and a secondary frame having parallel side guideways extending from the main frame for slidably supporting the gate as it is moved to and from an open position, the improvement in means for operating the gate which comprises a rotatable threaded operating shaft extending transversely of said parallel side guideways of said secondary frame and transversely of the path of movement of said slide gate, a pair of slide members mounting said rotatable operating shaft on said parallel side guideways of said secondary frame for sliding movement toward and away from said main frame, thrust bearing means threadably mounted on said operating shaft, force reaction linkage means pivotably interconnected between said thrust bearing means and the end of said secondary frame furthest from said discharge opening, and force transmitting linkage means pivotably connected at one end thereof to the trailing edge of said slide gate and pivotably connected at the opposite end thereof to said thrust bearing means so that rotation of said thrust bearing means with said shaft is prevented whereby rotation of said shaft results in nonrotational axial movement of said thrust bearing means along said shaft and simultaneous relative movement between said slide gate and said shaft toward or away from each other due to said force reaction linkage means and said force transmitting linkage means.

2. The improvement of claim 1, wherein said operating shaft has a right-hand threaded section at one end and a left-hand threaded section at the opposite end, wherein said thrust bearing means is comprised of a pair of thrust bearing members one each threadably mounted on each of said threaded sections of said operating shaft, and wherein said force transmitting linkage means is comprised of a pair of links each of which is connected between one of said thrust bearing members and a trailing corner of said gate.

3. The improvement of claim 1, wherein said force transmitting linkage means comprises a pair of force transmitting link members each individual to one of a pair of thrust bearing members and each being pivotally connected at one end to the latter and pivotally connected at the other end to the slide gate, and wherein said force reaction linkage means comprises a pair of force reaction link members each individual to one of said thrust bearing members and each being pivotally connected at one end to the latter and pivotally connected at the other end to the secondary frame.

4. The improvement of claim 3, including auxiliary link members individual to each force transmitting and each force reaction link member and each being pivotally connected at one end to the latter intermediate the ends thereof and pivotally connected at the other end to the adjacent shaft-supporting slide member, whereby to stabilize movement of said slide gate. 

1. In a hopper outlet assembly including a main frame having a discharge opening through which lading can flow by gravity, a slide gate slidably movable between closed and open positions relative to the discharge opening, and a secondary frame having parallel side guideways extending from the main frame for slidably supporting the gate as it is moved to and from an open position, the improvement in means for operating the gate which comprises a rotatable threaded operating shaft extending transversely of said parallel side guideways of said secondary frame and transversely of the path of movement of said slide gate, a pair of slide members mounting said rotatable operating shaft on said parallel side guideways of said secondary frame for sliding movement toward and away from said main frame, thrust bearing means threadably mounted on said operating shaft, force reaction linkage means pivotably interconnected between said thrust bearing means and the end of said secondary frame furthest from said discharge opening, and force transmitting linkage means pivotably connected at one end thereof to the trailing edge of said slide gate and pivotably connected at the opposite end thereof to said thrust bearing means so that rotation of said thrust bearing means with said shaft is prevented whereby rotation of said shaft results in nonrotational axial movement of said thrust bearing means along said shaft and simultaneous relative movement between said slide gate and said shaft toward or away from each other due to said force reaction linkage means and said force transmitting linkage means.
 2. The improvement of claim 1, wherein said operating shaft has a right-hand threaded section at one end and a left-hand threaded section at the opposite end, wherein said thrust bearing means is comprised of a pair of thrust bearing members one each threadably mounted on each of said threaded sections of said operating shaft, and wherein said force transmitting linkage means is comprised of a pair of links each of which is connected between one of said thrust bearing members and a trailing corner of said gate.
 3. The improvement of claim 1, wherein said force transmitting linkage means comprises a pair of force transmitting link members each individual to one of a pair of thrust bearing members and each being pivotally connected at one end to the latter and pivotally connected at the other end to the slide gate, and wherein said force reaction linkage means comprises a pair of force reaction link members each individual to one of said thrust bearing members and each being pivotally connected at one end to the latter and pivotally connected at the other end to the secondary frame.
 4. The improvement of claim 3, including auxiliary link members individual to each force transmitting and each force reaction link member and each being pivotally connected at one end to the latter intermediate the ends thereof and pivotally connected at the other end to the adjacent shaft-supporting slide member, whereby to stabilize movement of said slide gate. 